Population fluctuations
The island population grows, the island population shrinks. Boone’s death was the first of the major characters to be killed off, or if you’re to believe Jack, to be murdered. However we know that although Locke asked Boone to investigate the plane, it wasn’t his fault that it fell and crushed him. Also on the ‘murdered’ point, its interesting then that Boone’s step sister Shannon died after being “accidentally” shot by Ana-Lucia, again maybe not murder but Ana-Lucia was aiming to kill what ever she hit, she just thought she was shooting the “bad guys”. Ana-Lucia however was most definitely murder, and Michael didn’t mess around, promptly killing Libby, presumably because she witnessed the first one. It will be interesting how everyone reacts when Michael returns in Season 4.